Santorum, Romney allies going all-in in Michigan

UPDATED 6:20 PM ET...The game of Poker in Michigan between Romney and Santorum allies just got a little richer.

The pro-Romney Super PAC Restore Our Future just bought up almost another $1 million in ad time in Michigan, bringing its overall buy so far to about $3.2 million, according to NBC/Republican ad-tracking firm Smart Media Group Delta.

This follows the Santorum campaign pushing more of its own chips in, adding $438,000 in ads in Michigan for the next two weeks, closing the gap with Romney and his allies somewhat.

Restore shelled out another $2 million for the week after next on broadcast in Arizona, Ohio, Georgia, Oklahoma, Mississippi, Tennessee, and Alabama. Restore has now crossed the $20 million threshold for total ad spending this campaign -- $20.8 million.

Romney's campaign has now spent $13.4 million, bringing pro-Romney spending to a grand total of $34.2 million.

The next closest is $7.8 million in pro-Gingrich ads ($5.1 from Winning Our Future and $2.7 million from the campaign); then it's $6.1 million for Ron Paul; and $4.2 million for Santorum ($2.1 million apiece for the campaign and Red, White, and Blue Fund).